The modern manufacturing industry relies heavily on computer numerical controlled (CNC) machining tools and operations, particularly in the fabrication of metal components. An integral part of such machining processes is the use of cutting fluids. In particular, dating at least back to the work of F. W. Taylor in 1907, it was identified that if a fluid is applied to a cutting tool during a machining operation, the tool life can be increased, even if the fluid is water. Significant research has been conducted since that time to identify particular chemical compounds—including oils—that further the goal of increased tool life. Moreover, such research has expanded beyond the mere goal of improved tool life as the use and formulations of cutting fluids are also impacted by goals of obtaining higher quality surface finishes and reducing required cutting forces.
In a typical arrangement, a traditional CNC process applies cutting fluids using a flood application. In particular, a cutting fluid system within a CNC machining center applies a heavy and continuous jet or stream of cutting fluid to a cutting zone. The applied cutting fluid can facilitate cooling and/or lubrication of the cutting tools, and can also facilitate removal of chips of the cut-away materials. For instance, the cutting fluid may exit the cutting zone and carry the machined chips under gravity flow and into a chute where the chips can be filtered from at least some of the cutting fluid.
While a flood application of cutting fluid may generally be considered as facilitating the obtaining of desired results in terms of tool cooling and lubrication, obtaining those results can come at a significant cost. Such costs may be direct as well as indirect. For instance, resulting from the continuous stream of cutting fluid during machining, enormous quantities of cutting fluids can be consumed. Indeed, in some cases, cutting fluids may flow at a rate of over five liters per minute. Even where some of the cutting fluids can be cleaned and recovered for recycled use, a cutting fluid system used with a CNC machine may consume a large amount of cutting fluids. The cutting fluids carry with them direct costs not only in terms of the amount required to buy the fluid, but also the cost associated with storage and handling the cutting fluid. A machine shop may need to store large amounts of cutting fluid on the shop floor for all the manufacturing operations, thereby consuming valuable floor space. Used cutting fluids are also collected from the machines for recycling or disposal, and the reservoirs storing the reusable or disposable fluid also consumes floor space.
Additional costs may be incurred as a result of the handling processes used in connection with cutting fluids. Cutting fluids may contain hazardous wastes, so specific procedures may be implemented to handle the cutting fluids. Additionally, material chips may be recycled; however, because they can be covered in cutting fluids, specialized or costly equipment may be required to remove the cutting fluids, including residues or byproducts, from the chips and then to dry the chips that are fit for recycling.
On a global level, there is a groundswell of support for environmentally benign manufacturing processes. For metal machining manufacturing, the extreme consumption of cutting fluids, as well as the hazardous nature of some cutting fluids or cutting fluid components places such processes outside the realm of environmentally benign or sustainable processes. For instance, cutting fluids can pose environmental and economic risks as a result of toxic mist generation, liquid waste disposal, reduced recyclability of chips, and high maintenance costs.
Research into bringing metal machining into alignment with environmental and sustainability initiatives has result in some additional options for machine shops. For instance, one option is known as minimum quantity lubrication (MQL) which uses small amounts of lubricant in an atomized spray. Such a process greatly reduces the amount of fluid used; however, the process may primarily provide lubrication while being less effective in providing cooling to the cutting tool and/or work material. Due to reduced cooling, there may be thermal build-up that results in increased tool-wear, thermal distortion of work parts, and other less than desirable effects.
Other research has been conducted by advocates of “dry” or “near-dry” machining. Other efforts have been made to develop biodegradable cutting fluids. However, even bio-degradable cutting fluids are not totally safe as they may become mixed with machine oils, grease and lubricants used in machining.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.